When completing a sprint and selecting that unresolved issues be assigned to a future sprint does future sprint have to be active?
Do all the issues to be reassigned need to be part of the board you are completing sprints on? It doesn't seem like this would be the issue as it indicates the correct number of issues to be handled.
My last two sprints that I have completed and selected the future sprint - the sprint does not actually get assigned. I have had to manually go through the issues and add the new sprint. Would bulk edit but that wipes out the old history of past sprints.